During oral procedures, the dentist encounters many unique surgical difficulties. For instance, the oral cavity is a small space within which to work; it is bacteria laden and rich in blood supply; there is saliva, debris and applied fluid and aerosol buildup; and, finally, many patients have difficulty in keeping their tongues from entering the operative field.
Over the years, many appliances have been devised to assist in maintaining a clear and clean operative field. One example is seen in U.S. Pat. No. 1,042,133 to Marshall. This patent discloses a device for working on a patient's lower front teeth. This device includes a saliva ejector and a lower lip deflector and consists of a hollow double-bow tube having an exterior portion and an interior portion. The interior portion passes over the lower front teeth and rests below the tongue. The exterior portion has a lower lip deflector which hooks over the patient's lower lip exposing the front lower teeth. While this device is suitable for working on the front lower teeth, it has no application for use with the upper teeth or on lower teeth other than the front teeth. An additional shortcoming of this device is that it only provides for evacuation of fluid collecting near the lingual mucosa at the base of the tongue.
Two more examples are seen in U.S. Pat. No. 1,401,646 to Roan (a saliva ejector for use in dental procedures involving the lower jaw; it consists of two perforated tubular portions, one of which is disposed on the lingual side of the alveolar ridge and the other on the buccal side of the alveolar ridge. Optionally included is a tongue deflection plate) and U.S. Pat. No. 2,830,371 to Dahl (a variation of a hollow tube saliva ejector system having a tongue holder; this device further including a chin plate). While these two devices offer certain advances, they are not without shortcomings. First, they are satisfactory for use only in lower jaw procedures. They have no application for upper jaw procedures. Second, while the devices offer some tongue retraction capabilities, they do so by tongue depression. Tongue depression can be quite uncomfortable for the patient and is only a marginally effective technique since a patient's tongue can slip from beneath the depressor. Third, both devices only provide for evacuation of pooled saliva and fluid, with Dahl doing so only on the buccal side of the gums. Finally, neither device permits retraction of the cheeks. Thus, the devices do not significantly increase the size of the operating field.
Another example is seen in U.S. Pat. No. 3,090,122 to Erickson which teaches a dental appliance that provides for the collection and drainage of liquid and debris, partial retraction of an adjacent cheek and depression of the tongue, and a bite support to maintain the device's position and the patient's mouth open. A shortcoming of this device is that it requires the patient bite down on the device to hold it into place. This can lead to patient discomfort and movement of the device. A further shortcoming of this device is the placement system may cause obstruction of the operative field. A further shortcoming of this device is that it only retracts a small portion of the tongue and provides essentially no retraction of the cheek, thereby only slightly increasing the operative field. A final shortcoming of this device is that it collects only collected fluid and debris.
A further example is seen in U.S. Pat. No. 4,053,984 to Moss. This patent teaches a mouth prop consisting of upper and lower U-shaped sections, the sections having apertures for extracting fluid and debris, cheek deflectors, a tongue depressor, and upper and lower lip deflectors. While this device is an improvement in the art field, it is not without its shortcomings.
A first shortcoming is that the device provides for tongue depression instead of retraction; the drawback of which is discussed above. A second shortcoming is that the device fits around the front of a patient's mouth, thereby creating a potential obstruction to the operating field. Another shortcoming of the device is that while providing for cheek retraction, it does so only passively, thus it only minimally increases the size of the operating field. A last but significant shortcoming of the device is that while providing for fluid and debris evacuation at not only the mandibular level but also the maxillary level, it does so at only one suction volume. Thus, there is no ability to adjust suction flow volumes to maintain the optimum flow for a given area.
Examples of other prior art are found in U.S. Pat. Nos. 4,259,067, 4,260,378, 4,632,093, 4,992,046, 5,037,298, 5,232,362, and 5,460,524.
While the prior art provides certain advances in isolating oral tissue and evacuating saliva from an operative field, the prior art suffers five general shortcomings. First, while increasing the size of the operative field somewhat, none of the prior art maximizes the size of the operative field. The prior art generally provides only discomfort causing tongue depression and, at best, minimal cheek retraction. Second, the prior art, in some fashion or another, obstructs the operative field in which a dentist must work. Third, the prior art is all designed to be fixed in shape. It forces the patient's mouth to conform to it as opposed to the device conforming to the patient's mouth. Fourth, the devices which provide for saliva evacuation generally do so only in a passive sense. The devices are designed to fit on either the lingual or buccal mucosa near the base of the alveolar ridge. These designs only enable the devices to extract saliva and debris which have, through gravitational flow, settled in the bottom of the mouth. This is often ineffective inasmuch as a comfortable operating angle requires that a patient's head be tilted somewhat backwards. Thus, the saliva and debris do not always congregate or collect in a position convenient for evacuation by the device.
Fifth, the prior art that does provide an evacuation means other than in the floor of the mouth, does so only at the same suction volume as that of the lower jaw saliva evacuation. This invariably leads to a situation in which the misting aerosol spray, which keeps drill bits and teeth cool and clears away debris, is not efficiently evacuated from the operating field. If the suction flow rate is increased sufficiently to remove the misting spray, the suction apparatus positioned near the base of the mouth will create a seal with surrounding tissue, resulting in tissue damage and preventing removal of collected saliva and debris. If, on the other hand, suction flow is decreased to a level in which accumulated fluid can be extracted, the suction flow rate is ineffective at evacuating misting aerosol spray.
There is need, therefore, for an oral isolation device which provides an optimal size to the operative field by retracting both the tongue and the cheek adjacent to preselected oral tissue, maintains a clear operative field by creating no obstructions, and enables efficient simultaneous evacuation of saliva, aerosol, and debris from the base of the mouth and from the oral cavity.